The invention relates to an operating mechanism for a pivotable sliding panel of a vehicle roof with an electric motor driving the panel whose both terminals can be connected through first and second interconnectors by means of a reversing switch selectively to different poles of a power source in order to be able to reverse the direction of rotation of the motor and with it the direction of motion of the sliding panel. In order to attain an automatic switching off of the motor in the closed position of the panel, and regardless whether the panel goes into the closed position from a pivoted position or from a slid back position, in the first interconnector between the motor and the reversing switch a first switch is arranged which is operated by an impulse relay whose control winding is connected on the one hand to the first interconnector between the first switch and the reversing switch through a first connecting line and on the other hand to the second interconnector through a second connecting line in which a second switch is provided which is operated via a control member driven by the motor in such a way that the said switch is closed in the closed position of the sliding panel, yet open during the opening and closing process. Such an operating mechanism is described in commonly assigned U.S. Pat. No. 3,702,430 (corresponding to German Patent Application No. P 21 00 336. 1).
A certain problem is pivotable sliding panels resides in the fact that the path of the driving means (such as a stiff, push-pull cable) moving the panel is substantially shorter for the pivoting movement of the panel than for the sliding movement of the panel, with the result that at equal speed of the driving means the time required for the pivoting of the panel is substantially shorter than the time required to slide back the panel. The consequence of this is that the pivoting motion of the panel cannot be as sensitively controlled as the sliding motion. The problem described was already solved for sliding panels driven by a hand crank in that one provided for an additional gearing step for the pivoting motion of the panel between the crankshaft and the driving pinion, which causes the gearing to become slower, see DT-OS (German Offenlegungsschrift) No. 2,447,190. The incorporation of such a working gear stage would also fundamentally be possible in a sliding panel driven by an electric motor, however, such an expense does not seem warranted.
The invention has taken on the task of extending the duration of the outward pivotal motion of the sliding panel in a simple manner with an operating mechanism constructed according to the above-noted U.S. Pat. No. 3,702,430.
In accordance with the invention, the above-noted problem was solved in that speed reducing means for reducing the speed of the motor are provided for, which speed reducing means can be switched on by the control member when it moves out of the position corresponding to the closed position of the panel in the sense of a pivoting of the panel.
Through the suggestion in accordance with the invention a slow pivoting of the panel and with it a more sensitive steering or control are accordingly made possible as in the previously mentioned mechanically-driven sliding panel.
According to a preferred embodiment, the speed reducing means for reducing the speed of the motor is formed as an electrical resistor inserted in an interconnector. According to other preferred embodiments an electronic control element such as an electric pulse generator or longitudinal control with transistor or another familiar electronic means, are provided for instead of the electrical resistance to regulate motor speed. Another alternative embodiment consists of employing a motor with two windings, one for high and one for lower speed, whereby the winding for lower speed is switched on to pivot the panel, while the other winding is switched on for longitudinal movement of the panel.
The speed reducing means for reducing the speed of the motor is also preferably additionally switched on when the panel nears an end or closed position and, in fact, independently of whether the pivoting or sliding motion is involved. Thus a gentle closing of the panel or a gentle movement in the appropriate end position results.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a single embodiment in accordance with the present invention.